Dental casting-machine.



W. F. LAWRENZ.

DENTAL CASTING MACHINE; APPLICATION FILED JUNE20,1907.

Patented oet. 4, 1916.

2 SHEETS-SHEET l.

LAWRENZ.

DENTAL GASLING MAGHNE.

APPLICATION FILED JUNE 2o, 1907,

EN STEES ATENI FFQE.

WILLIAM F. LAXVRENZ, OF ST. LOUT, MISSOURI, ASSIGNOR T0 JAMES A. CARR, OF ST.

Louis, MISSOURI.

DENTAL CASTING-MACHINE.

.To all whom it 'may concern:

lle it known that l. illumini ll`. Lxwnlnxz, a citizen oii the Vlli'iited States, and a resident of the city ot St. Louis and State ot l\'lissouri, have invented a new and usei'ul lmprovement in Dental Casting-Machines, ot which the following1 is a specitication.

rlhe principal object ot my invention is to facilitate the shaping ot plugs for cavities in teeth,

lt consists principally in arranging' an air compressor adjacent to a crueihle and a mold so that the metal on thc erucihle may lic forced into the mold.

lt also consists in the parts and in the arrangements and combinations ot parts hereinafter described and claimed.

In the i accompanying drawing, which forms part of this specification. and wherein like symbols` reit'er to like partsl wlmi-ever they occur7 Figure l is a side elevation of a niacliine embodying my invention. with the parts in their highest. positions: Fir. 2 is a front; elevation thereof with the parts in their highest positions.; itig'. il is a trontelcvation of the parts with the pump cylinder in its lowermost position. This view also indicatesI in dotted lines the lower position of the tappet frame; Fig. t is an enlarged vertical sectional detail view through the upper portion of the pump cylinderand adi jacentJ part-s; Fig. 5 an 'enlarged vertical sectional View through the upper portion of the machine; Fig. ti is an inviated vertical sectional view through the mold ta li showing the wax pattern in position; Fig'. i is a similar view with the investment material surronndiirll the wax pattern.

The trame oi. the machine con'iniises a verticzlly arranged c yflindi'ica|V shell por- `tion l provided 'with a bracket 2 or other suitable means ot' support. ln the upper portion of this c vlilulrical shell is a pump cylinder il which is arranged to reciprocate vertically therein. For this purposIv the cylindrical shell is provided with longitudinally arranged slots l through which cx* tend pins 5. which are tlxed to the pump cylinder and which are connected to down- 1wardly extcnduiggl rods (i on the exterior of the cylindrical shell. y'llhese rods extend through a cross-plate 7 and have. their ends threaded to receive nuts 8 which serve to adjust and hold the cross-piece on the rods. The cross-piece is perforated to slide on a Specification of Letters Patent.

Application filed June 20, 1907.

Patented Oct. d, i919.

serial No. 379,855.

vertical guide t) and is connected by a helical spring' l() to a linkl or chain ll which is connected to a toot lever l2. By this arrangement, thc dowmvard movement of the foot lever is transmitted through the chain7 the spring. the cross piecev and the rods to the pump cylinder to move said cylinder down wardly in the frame.

Inside ot the pump cylinder is a piston or plui'iger 13 'whose rod lil. extends through the upper end oi the pump cylinder and the supporting 'trame and is provided'with a shoulder or tappct ll thereon. rThe end et this piston rod extended or provided with an extending member 15 which extends through a recil'irocating cross-head lo constituting a member ot' a tappet frame. This rccilnocatingA cross -head is eoiniected by downwardly extending' side rods 17 to a second cross head 18 arranged to reciprocate over rods t3 and guide t). ,lh'eterahl v, the tappet trame has two side rods on each side. and each paiil ol rods is arranged to straddle the guide pin which extends' outwardly troni the pump cylinder through said cylindrical shell of the device. head lo of this reciprocating tappet Vtrame is perfo ated to slide'on the guide f) and is provided with a spring clamp 1i.' or other suitable friction device arranged to bear against the o'uide and thereby bind and hold the tappet frame at any position to which itin-.1y he moved. The. lower end ot' thisl tappettrame is connected hy the iink or chain 1l and a chain 2() directly to the treadle or toot lever l2 hereinhelore mentioned. As this tappet frame and thc pump cylinder are both actuated hy the same foot lever, a certain amount ot slack is provided in the chain above its insure a downward movement ot"l the tappet frame after the downward Vmoven'ient of the pump cylinder is completed. During the downward inoven'ientot the pump cylinder, the pump piston travels therewith on accountI of their frictional engagement. rilhe downward movement of the piston through its cylinder begins atter the cylinder reaches its lowerxnostposition and is caused by the upper cross-head of the tappet traine hcaring against'v the shoulder on the piston rod. The slack in the chain and the extensibility of the helical Spring` ments.

The lower portion of the cylindrical shell point of connection with the spring` so to provide for these inove- The lower cross` f llO or rarie of tlie machine is arr., ed ceive the mold flask Q1 with tiie neil-o uppermost7 and tbe side of tlie cjyliu shell or i" une is open so as to permit access 'to tbe Crucible 222. 'ilie crucible end or the molti iaslg is of the saine size as the lower cui ofthe pump cgflin aud sucli ends are provided, "with cout teipart bei/ele or form a tigut joint. A rubber gasket be used to insure an air tight "llieniolfl ila l: is short tubular er lr'cal sliell Yrliicli ie counterbored or rovine-1l simule fil tlironili of tbe conca'rit): 25

un. w.

occasion.

'llie mold is prepared Lin tlie f/ manner. fi wax model or 'p n ing for tlie 'tooth cavity; is iirs usual way and tlien iuipaleIV piece of wire or other sin..

a lapteti to lit into the sprue li cible This Wire is then me. Luie lioie with the Wax pal lie mold flask. llie wat i; carefully coated with a tliin lajier a able investment material and tlic mold (with tlie Crucible end Clown) is t-lieii i. with said investment material. l suitale investi .eut material consists of one part oi suiiicient Water to gire it a convenient we le ,L ino' coi sistencjl. The mold is then dried out .f1 fw if i .i @will Li il i i. ano meteo o neab suucnin. ionen 1 u, Wax pi 'tern @n account. of tlic porosi of the i s i'vcstn'ient material the molten nag i.' soon entirely absorbed iliei'ein. lraifing z cavity of the size and shane of tlie cavity in tlie tooth to be ifilled. The outnfardlv projectingff end et tliewire that constituted tlic support toi tlie wax pattern is tlieii A:gripped with a suitable instrument and witlii'lrawn from tlie crucible.y leaving` the mold and crucible ready tor insertion into tlic casting inaeliine,

. The manipulation of the niacliine is as follows: llie parts are manuali)7 aised to their highest positions where they are normally lield by friction, and the niold llasli is inserted in the` machine.. The gold t'or the plug` is tlien laid on the Crucible .Yliicli 1' xadily accessible in this position oi the parts.

l E compress-es tbe The gol/ is tlueri melted Wiiia Slow pipe or other su lol-e means and the operator presses liis oot against the foot lever. The initial portion of the movement of the toet lever is transniiated tlirougli tlie ten# sion. spring' and the freine connected thereto er. which nieves clown:

to tbe pump cylineV l uf'ardly and t'ornis a tight joint with the upper edge of tlie mold iiasle is soon` as the slack in the chain et ti e tappet traine is talen up,

i tbe. tappet. frame is moved downwardly, and as ii strikes the shoulder et tlie con is that, itj

forced f owuwz r cylinder. Z-lie -iir acts against 3 cylinder is aetuaeeel mug, a nvaried by ineens dusting Working on the tbreadedl'entis of the rods .vliicli position the plate to wliieli the i is connected. ly suitably adiusting `Jet-e, the actuation ot tlioupuinp cy incier can le fl' t? i the movement o't l e :t e @tuer adjustnenis a J `eqn liliile my Cle/'ice is i articnlarly designed l :tor the use of dentists and is obvious that it may be used ot er articles than tooth iillings J D and otlier of guia, and l do no wi l. te be i ed to sur So too, itr is obi i. ni'iuerous ianges nay be merle 1 the va. 'ous portions et' the conn struction i efoie described.; and l do be restricted to the siruc4 ithereof.

lliat l claim as nio; i ir-enti( and cesire to secure by Lette Si casting ina bine combining an 1nter, al tubular iuold open at o1 e end, a crucibie constitutingthe other end et saio niold and haring a spruc hole communicating with said mold an air lier-essor, and

the pressure et air lo the ci'ucibie.

uaclune coninrisinff an niaj.' be

. crucible in aule cylinder blc, and means said cylinder Fil.)

@new

tive te aid mime .and arranged te sen the same, a piston in said cylinder, means for moving said cylinder and iston simultaneously toward said crucib e, and then moving said piston in said cylinder to compress the air therein after said crucible is sealed.

4. A casting machine comprising a frame adapted to receive a. mold, an air compressor slidingly mounted in said frame and having a member adapted to form an airtight connection with said mold, and means for moving said compressor into operative position and then actuating the air compressing member thereof.

5. A casting machine comprising a frame adapted to receive a mold, a cylinder mount- -ed 1n said frame, and movable toward and from said mold, an air compressor in said cylinder, means for forming an airtight connection between said cylinder and said mold, and means for actuating said air compressor after said airtight connection is made, whereby the surface of the mold is subjected to the pressure in said cylinder.

6. A casting machine comprising a frame,

a combined mold and Crucible therein, an air compressor `mounted on said frame .and comprislng means for forming an airtight connection between said air com ressor and said mold outside of the cruci le thereof, and means for actuating the air compressing member of said compressor after such airtight connection is made, whereby the mold is sub'ected to the ressure.

7. 1i casting mac vine comprising a frame having a ycylindrical shell, a mold. flask adapted to fit in said shell, a. cylinder slid*A ingly mounted in said shell and adapted to form an air tight joint with said mold flask, a leverl having an extensible spring connection with said cylinder, a piston in said cylinder and movable therewith, and a tappet frame connected to said lever to actuate said iston after the cylinder has formed its Joint with said mold flask.

Signed at St. Louis, Missouri, this 15th day of June, 1907.

WILLIAM F. LAWRENZ. l/Vitnesses:

J. B. MEGOWN, Gr. A. PENNINGTON. 

